Environmental concerns have come to prompt an increase in the proportion of energy derived from natural sources.
However, natural energy tends to be influenced by changes in climate. Power companies thus need to have reserve power-generation facilities in order to realize stable supply, and the cost of energy supply increases.
Demand response is a contrivance by which a consumer side is requested to adjust an amount of demand in correspondence with variation of the amount of supply in order to handle such cost increase. For example, Japanese Laid-open Patent Application No. 2011-193577 proposes a lower-level apparatus in which an amount of demand is adjusted during a prescribed period in order to suppress the amount of energy increasing in accordance with a season and/or time period. The consumer can obtain a discount or other incentive by thus complying with the request for demand response from the power company.